Pendant arm systems are used in healthcare facilities to provide stable suspended equipment platforms. Pendant arm systems are often suspended from ceilings walls to provide maximum equipment access without cluttering floor space. Pendant arm systems typically have a central pivot that has independently rotatable shoulder castings, to which pendant arms modularly attach. Wiring is usually run from a wall or ceiling to the equipment, where such wiring can be used to deliver power, control, or audio/video signals. Previous pendant arm systems have run their cabling externally to the shoulder castings.